Saliva specimens are obtained from both cases and controls and their biological mothers. The saliva samples are sent to the study office and processed in the Genetic Epidemiology lab at UC Berkeley. DNA from cases and controls will be analyzed by polymerase chain reaction for genetic polymorphisms. Genetic polymorphisms will be examined in two glutathione transferase genes, M1 and Tl. Case samples of peripheral blood, bone marrow, and archived newborn blood will be also used to detect N-ras mutation.